title: Reaction of the 4-biphenylnitrenium ion with 4-biphenyl azide to produce a 4,4'-azobisbiphenyl stable product: a time-resolved resonance Raman and density functional theory study.
abstract: A time-resolved resonance Raman (TR(3)) and density functional theory (DFT) study of the reaction of the 4-biphenylnitrenium ion with 4-biphenyl azide in a mixed aqueous solution is reported. The reaction of the 4-biphenylnitrenium ion with its unphotolyzed precursor 4-biphenyl azide in a mixed aqueous solution generates a 4,4'-azobisbiphenyl stable product via an intermediate species. With the aid of DFT calculations for likely transient species, this intermediate was tentatively assigned to a 4,4'-azobisbiphenyl cation. The DFT calculations predict this reaction can take place via two pathways that compete with one another to produce the trans and cis 4,4'-azobisbiphenyl product. The observation of the 4,4'-azobisbiphenyl cation intermediate demonstrates that the reaction of the arylnitrenium ion with its aryl azide to produce a stable azo product occurs via a stepwise mechanism.
authors.affiliation: Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, PR China.
authors.forename: Jiadan
authors.initials: J
authors.lastname: Xue
authors.forename: Yong
authors.initials: Y
authors.lastname: Du
authors.forename: Xiangguo
authors.initials: X
authors.lastname: Guan
authors.forename: Zhen
authors.initials: Z
authors.lastname: Guo
authors.forename: David Lee
authors.initials: DL
authors.lastname: Phillips
mesh_terms: D000611:Aminobiphenyl Compounds / Q000737:chemistry*; D001386:Azides / Q000737:chemistry*; D001391:Azo Compounds / Q000737:chemistry*; D001713:Biphenyl Compounds / Q000737:chemistry*; D011789:Quantum Theory; D013059:Spectrum Analysis, Raman; D013237:Stereoisomerism; D013997:Time Factors
chemical_list: C534912:4,4'-azobisbiphenyl; D000611:Aminobiphenyl Compounds; D001386:Azides; D001391:Azo Compounds; D001713:Biphenyl Compounds; C006757:4-biphenylamine; C077839:4-azido-1,1'-biphenyl